Battery light stays on

[i_zombi]

When I start my car, my battery light stays on.
I replaced the battery, still on.
Even with jumper cables to it it stays on.
I believe my alternator may be bad, would that cause it?
Thanks
Dan

 

[spipedong]

Bingo, the battery light indicates that the battery is not being charged. A dead alternator would definitely cause that.

Oh and for some reason it's usually accompanied by the brake light. Don't ask me why.

 

[i_zombi]

I bought a used alternator off someone on this forum.
Autozone tested it, said it was bad.
I went to advanced, they said it was charging at 17 volts.
This seems excessive to me, is it?

 

[spipedong]

I would think thats a little excessive if its true...

Most alternators are designed to charge at 13.6 volts.

 

[i_zombi]

Thats what I thought, Guess I'll getter rebuilt.
Thanks

 

[i_zombi]

Bingo, the battery light indicates that the battery is not being charged. A dead alternator would definitely cause that.

Oh and for some reason it's usually accompanied by the brake light. Don't ask me why.

And wouldnt you know my brake light stays on also.
It just gets a tiny bit brighter when the e brak is applied.

 

[canadian]

Same thing happened to me with both my battery light and the brake light...but I have a whole list of other problems...

 

[akito]

^^^^our projects.......lol

 

[Jeff Lange]

And wouldnt you know my brake light stays on also.
It just gets a tiny bit brighter when the e brak is applied.

It is designed that way. There is a diode between the brake and charge light. It's so that when you turn the key to "ON" all the lights come on so you know if any are burnt out. Toyota did it on most of their cars.

The charge light cannot come on without the brake light coming on. The reason the brake light gets slightly brighter when you pull the e-brake is because Diodes have a 0.7V drop across them, so there is slightly more current flow when the brake is pulled.

 

[Yellow 13]

It is designed that way. There is a diode between the brake and charge light. It's so that when you turn the key to "ON" all the lights come on so you know if any are burnt out. Toyota did it on most of their cars.

Know it all...









:biglaugh:

 

[rakkasan]

It is designed that way. There is a diode between the brake and charge light. It's so that when you turn the key to "ON" all the lights come on so you know if any are burnt out. Toyota did it on most of their cars.

The charge light cannot come on without the brake light coming on. The reason the brake light gets slightly brighter when you pull the e-brake is because Diodes have a 0.7V drop across them, so there is slightly more current flow when the brake is pulled.

Are you sure you didn't design the MKIII?

 

[suprasport91]

and everythin toyota for that matter..

 

[i_zombi]

It is designed that way. There is a diode between the brake and charge light. It's so that when you turn the key to "ON" all the lights come on so you know if any are burnt out. Toyota did it on most of their cars.

The charge light cannot come on without the brake light coming on. The reason the brake light gets slightly brighter when you pull the e-brake is because Diodes have a 0.7V drop across them, so there is slightly more current flow when the brake is pulled.

Very useful information. Thanks for the post.
Does that have any thing to do with the brake light failure light?
Dan

 

[jdub]

Very useful information. Thanks for the post.
Does that have any thing to do with the brake light failure light?
Dan

Yes...a bad alternator will cause both the charge light and the brake light to come on.

 

[i_zombi]

Yes...a bad alternator will cause both the charge light and the brake light to come on.

 

[i_zombi]

Wow, it seems like the alternator is the life line of everything electronic.
Thanks
Dan

 

[Jeff Lange]

Yes...a bad alternator will cause both the charge light and the brake light to come on.

Brake light failure light is not brake light, it's totally seperate.

 

[jdub]

Brake light failure light is not brake light, it's totally seperate.

Actually the red light on the speedo is called "Brake System Warning Light"...this is what I thought he was talking about based on Post #6.

The yellow tail light in the cluster with the "Engine System Warning Light" (or Check Engine Light) is called "Rear Light Failure Warning Light"...it illuminates when a tail light or brake light is burned out.

 

[Jeff Lange]

Key word there being failure I think.

 

[Big Wang Bandit]

Yeah I noticed that My "brake" light came on when my brake fluid was low. Then they shitted out on me 3 seconds later...

:wtc: